/*
* Copyright 2013 Red Hat, Inc. and/or its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.optaplanner.core.impl.domain.solution.mutation;
import java.util.Iterator;
import java.util.List;
import org.optaplanner.core.api.domain.solution.PlanningSolution;
import org.optaplanner.core.impl.domain.entity.descriptor.EntityDescriptor;
import org.optaplanner.core.impl.domain.solution.descriptor.SolutionDescriptor;
import org.optaplanner.core.impl.domain.variable.descriptor.GenuineVariableDescriptor;
/**
* @param <Solution_> the solution type, the class with the {@link PlanningSolution} annotation
*/
public class MutationCounter<Solution_> {
protected final SolutionDescriptor<Solution_> solutionDescriptor;
public MutationCounter(SolutionDescriptor<Solution_> solutionDescriptor) {
this.solutionDescriptor = solutionDescriptor;
}
/**
*
* @param a never null
* @param b never null
* @return {@code >= 0}, the number of planning variables that have a different value in {@code a} and {@code b}.
*/
public int countMutations(Solution_ a, Solution_ b) {
int mutationCount = 0;
for (EntityDescriptor<Solution_> entityDescriptor : solutionDescriptor.getGenuineEntityDescriptors()) {
List<Object> aEntities = entityDescriptor.extractEntities(a);
List<Object> bEntities = entityDescriptor.extractEntities(b);
for (Iterator<Object> aIt = aEntities.iterator(), bIt = bEntities.iterator(); aIt.hasNext() && bIt.hasNext(); ) {
Object aEntity = aIt.next();
Object bEntity = bIt.next();
for (GenuineVariableDescriptor<Solution_> variableDescriptor : entityDescriptor.getGenuineVariableDescriptors()) {
// TODO broken if the value is an entity, because then it's never the same
// But we don't want to depend on value/entity equals() => use surrogate entity id's to compare
// https://issues.jboss.org/browse/PLANNER-170
if (variableDescriptor.getValue(aEntity) != variableDescriptor.getValue(bEntity)) {
mutationCount++;
}
}
}
if (aEntities.size() != bEntities.size()) {
mutationCount += Math.abs(aEntities.size() - bEntities.size())
* entityDescriptor.getGenuineVariableDescriptors().size();
}
}
return mutationCount;
}
@Override
public String toString() {
return "MutationCounter(" + solutionDescriptor + ")";
}
}